The following information is provided to assist the reader in understanding technologies disclosed below and the environment in which such technologies may typically be used. The terms used herein are not intended to be limited to any particular narrow interpretation unless clearly stated otherwise in this document. References set forth herein may facilitate understanding of the technologies or the background thereof. The disclosure of all references cited herein are incorporated by reference.
Graphene has attracted significant attention as a result of its novel electronic properties coupled with its mechanical strength. Both such properties may make graphene an important material in future generations of electronics, batteries, sensors, composites etc. One of the current methods of synthesizing graphene entails exfoliating graphite through oxidation to yield graphite oxide. That material is sonicated to produce graphene oxide. Graphene oxide is subsequently reduced either chemically or thermally to produce reduced graphene oxide (RGO).
While the graphene precursor, graphite oxide, has been studied for about 170 years, there is now emerging interest in graphene oxide and RGO. For example, graphene oxide has been proposed for drug delivery and cellular imaging applications. Further, graphene oxide paper formed from interlocking sheets of graphene oxide demonstrated superior strength and stiffness compared to many other papers. Finally, graphene oxide has been suggested as a simple alternative to poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), a hole transporting layer and electron blocking layer in organic photovoltaics (OPVs). RGO, on the other hand, has been employed for both chemical and biological sensing applications.
Graphene and graphene derivatives such as graphene oxide have been modified for applications through treatment with strong oxidizing and reducing agents, oxidative etching at temperatures greater than 400° C., etching using lithography, and sonochemical approaches.